TypeScript constructor parameters with public, private, and protected

A class constructor can automatically create and initialize class properties by using parameter property declarations .

public class Foo
{
    constructor(public bar: string, private baz: number, protected qux: boolean) {}
}

That is the equivalent of this:

public class Foo
{
    public bar: string; 
    private baz: number; 
    protected qux: boolean;

    constructor(bar: string, baz: number, qux: boolean) {
        this.bar = bar;
        this.baz = baz;
        this.qux = qux;
    }
}